Plunger Lift Lubricator

ABSTRACT

A plunger lift lubricator including a lower lubricator section having an internal lubricator bore extending axially from a top thread profile to a bottom flange profile an outlet pipe connector comprising a body having a vertical throughbore forming a portion of the lubricator bore and a radial passage extending through a pipe connector profile to the vertical throughbore.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application claims the benefit under 35 U.S.C. §119(e) of U.S.Provisional Patent Application No. 62/205,310, filed Aug. 14, 2015,which is incorporated herein by reference in its entirety as if fullyset forth herein.

BACKGROUND

This section provides background information to facilitate a betterunderstanding of the various aspects of the disclosure. It should beunderstood that the statements in this section of this document are tobe read in this light, and not as admissions of prior art.

Hydrocarbon producing gas wells generally produce liquids in addition tothe flowing gas stream. These fluids, gas and liquids, are conducted tothe surface by a string of production tubing that communicates the belowground formation to piping system at the surface. Removal of the liquidfraction of the fluid column is mandatory for maintaining theunrestricted production of gas from the production zone formation.Frequently, a beam pump unit is employed for this task. However, beampumping units are expensive and suffer from high maintenance costs.

In the field of plunger lift, a plunger acts as an unattachedfree-traveling piston within the length of the production tubing for thepurpose of lifting liquids from an active, gaseous hydrocarbon-bearingformation. In the life cycle of a plunger lift system, the plungertravels first downwardly to the bottom region of the tubing stringadjacent to the formation then upwardly within the tubing stringmultiple times within the course of the day. The use of a plunger withinthe tubing conduit of a gas well will enable the upward flow oflight-density gas to push toward the surface those heavier liquidswithin the tubing string.

The term wellhead lubricator can refer to the sealing and packing deviceatop the wellhead of a rod pumping unit where the polish rod enters thewellbore at the surface. In the field of plunger lift, a housing unitmounted atop a flowing gas well is also referred to as a lubricator. Theplunger lift lubricators extant are occasionally made as a single outletversion in a T-shaped arrangement wherein production fluids flow intothe T-shaped lubricator and thence into the surface piping. The upwardlytraveling plunger moves into the uppermost portion of this T-shapedlubricator and held in this uppermost position by the up-flowing gasstream. When the moving gas stream is terminated by the subsequentclosure of a valve within the surface piping downstream of thelubricator, the plunger falls into the wellbore by the force of gravity.

In a more common iteration, the common plunger lift lubricator isreferred to as a “dual outlet,” meaning that the lubricator has twoproduction passageways extending perpendicular from the main verticalsection. An example of a common lubricator 300, having dual outlets, isillustrated in FIG. 1. The common lubricator 300 includes a metalvertical flow body 302 having an uppermost end 304 and a lowermost end306, which are threaded (e.g., 2⅜ inch 8-round thread). A spring housing308 is threaded connected at the uppermost end 304. The two outlets 310,312 do not define a cross but instead are located one above the otheralong the length of the vertical flow body of the lubricator 300 and areseparated vertically by the approximate length of a common plunger(piston). The purpose of the dual outlet arrangement is to avoid flowrestrictions as the plunger enters into and remains in the lubricatorvertical section. A single outlet lubricator is subject to flowrestrictions, should the plunger come to rest across the opening of thesingle outlet.

The lowermost end of the common lubricator, made from metallic tubing,presents a seal-tight threaded arrangement for attachment to thewellhead. In a common alternate version, the lowermost end of the commonlubricator is first attached, by threading or welding, to a flange whichis subsequently bolted to the mating flange of the uppermost valve inthe wellhead. All common flanges are purchased as pre-threaded or asprepared for welded attachment. Welded connections are capable ofholding 10,000 psi.

In general, the uppermost section of the common wellhead assembly (e.g.,tree) that exists below these common lubricators presents a flange styleconnection as the preferred version within the industry because of thereliability and pressure holding capabilities of flange connections.Flange to flange connections are capable of holding 10,000 psi.

The outlet pipe connections 311, 313 oriented horizontally and attachedto the vertical section of the common lubricator are made by the use ofseal-tight threaded connections (2″ NPT) or with the aid of the weldingprocess. The connections, whether threaded or flanged, joining thelowermost section of these common lubricators to the uppermost end ofthe wellhead tree are made using seal-tight threaded components or withthe aid of the welding process to join the metallic tubing to the flangeon the lowermost end of the common lubricator.

The one or more threaded (2″ NPT) connectors 311, 313 (thread-o-lets) ofthe common lubricator 300 that are provided at the respective one ormore outlets 310, 312 are attached to the vertical section by welding315. This threaded adaptor 311, 313, welded to the vertical section,permits threaded piping to be connected. All appropriate passageways310, 312 are first drilled into the vertical section prior to thewelding process. In another common iteration, one or more horizontallyoriented flanged style outlet connectors may be used and are welded tothe vertical section of the common lubricator and later joined to thesurface pipe facility by mating to these flanged connections.

For the purpose of inspecting or removing the plunger, a catcher device316 is installed with the lubricator 300 to catch and hold the plungerin its uppermost position within the lubricator. This device is mostcommonly a spring-loaded pin that passes horizontally through theexternal wall of the lubricator and acts to pin the plunger against theopposite wall. The rounded end of the pin that makes contact with theplunger does not damage, nor is damaged, by impact with the plunger.

Limitations of the common plunger lift lubricators extant include theuse of the various threaded connections. The commonly used threadedpipe, National Pipe Thread (“NPT”), specifications describe a V-shapethread with a pressure containment rating of 5,000 psi (2″ NPT), whereasthe wellhead tree is commonly rated at 10,000 psi. Dissimilar ratingsinvite mistakes with potential for failure. A pressure-caused failurecan occur when a fracking operation is being conducted on a nearbywellbore and the fractures migrate through the hydrocarbon-containingsource-rock to a wellbore that has been completed by underrated surfaceequipment, including a lubricator with NPT, V-shaped threads.

Another limitation related to the use of a common lubricator involvesfailures related to misalignment in the several components of the pipingarrangement leading away from the wellhead and lubricator assembly. Theequipment and components that make up the totality of the wellhead andsurface facilities is supplied by a variety of vendors. This variety ofequipment is typically installed by third parties without completeknowledge of any limitations that should signal against alignment byforce. Forced alignment procedures can be the source of failures inpiping systems under cold stress. By its nature, threaded pipe is rigidand unforgiving with regard to misalignment. The exposed threadedsection of threaded pipe represents the weakest point along the lengthof the pressure-containing pipe and the most common location for stresscracking and failure.

Further limitations are related to the use of welded connections. Thewelding process creates a heat affected zone (“HAZ”) adjacent to theweld. The improper heating and cooling of this heat affected zonecreates internal stress within the material.

With or without the heat of the welding process, the materials of thesepressure containing lubricators are aggravated by a cold environment.Steel, when subject to temperatures for example below zero-degreesFahrenheit, becomes brittle. It is common for lubricators used in coldclimates to experience stress-inducing temperature swings from 100 to−20 degrees Fahrenheit in a matter of minutes, multiple times a day,from the intermittent flow of very warm production fluids in thepresence of sub-zero wind and blowing snow.

SUMMARY

A plunger lift lubricator including a lower lubricator section having aninternal lubricator bore extending axially from a top thread profile toa bottom flange profile an outlet pipe connector comprising a bodyhaving a vertical throughbore forming a portion of the lubricator boreand a radial passage extending through a pipe connector profile to thevertical throughbore. In accordance to aspects of the disclosure thelower lubricator section does not have any welds. In some embodimentsthe lower lubricator section is formed of a single piece of materialincluding the top thread profile, the bottom flange profile, and theoutlet pipe connector and the pipe connector profile.

In some embodiments the lower lubricator section includes the outletpipe connector formed of a single piece of material with the verticalthroughbore extending between a top surface and a bottom surface, a flowbody formed of a single piece of material having a vertical throughboreforming a portion of the lubricator bore and extending from the bottomflange profile to a top flange profile that is connected to the bottomsurface of the outlet pipe connector and an adaptor formed of a singlepiece of material having a vertical throughbore forming a portion of thelubricator bore extending from the top thread profile to a bottom flangeprofile that is connected to the top surface of the outlet pipeconnector.

This summary is provided to introduce a selection of concepts that arefurther described below in the detailed description. This summary is notintended to identify key or essential features of the claimed subjectmatter, nor is it intended to be used as an aid in limiting the scope ofclaimed subject matter.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosure is best understood from the following detaileddescription when read with the accompanying figures. It is emphasizedthat, in accordance with standard practice in the industry, variousfeatures are not drawn to scale. In fact, the dimensions of variousfeatures may be arbitrarily increased or reduced for clarity ofdiscussion.

FIG. 1 illustrates a prior art common plunger lift lubricator.

FIG. 2 illustrates a plunger lift well system incorporating a lubricatorin accordance with one or more aspects of the disclosure.

FIG. 3 illustrates a plunger lift lubricator having a lower lubricatorsection that is constructed of a single piece of material including thetop and bottom connection profiles and one or more outlet pipeconnectors in accordance with aspects of the disclosure.

FIG. 4 illustrates a single piece lower lubricator section including thetop and bottom connection profiles and more than one outlet pipeconnector according to aspects of the disclosure.

FIGS. 5 and 6 illustrate a single piece lower lubricator sectionincluding the top and bottom connection profiles and a single outletpipe connector according to aspects of the disclosure.

FIG. 7 illustrates a plunger lift lubricator having a lower lubricatorsection that is constructed of multiple elements interconnected withoutwelding in accordance with one or more aspects of the disclosure.

FIGS. 8 and 9 illustrate an example of a multiple element lowerlubricator section according to aspects of the disclosure including abore liner.

FIG. 10 illustrates an example of a plunger catcher in accordance to oneor more aspects of the disclosure.

DETAILED DESCRIPTION

It is to be understood that the following disclosure provides manydifferent embodiments, or examples, for implementing different featuresof various embodiments. Specific examples of components and arrangementsare described below to simplify the disclosure. These are, of course,merely examples and are not intended to be limiting. In addition, thedisclosure may repeat reference numerals and/or letters in the variousexamples. This repetition is for the purpose of simplicity and clarityand does not in itself dictate a relationship between the variousembodiments and/or configurations discussed.

As used herein, the terms connect, connection, connected, in connectionwith, and connecting may be used to mean in direct connection with or inconnection with via one or more elements. Similarly, the terms couple,coupling, coupled, coupled together, and coupled with may be used tomean directly coupled together or coupled together via one or moreelements. Terms such as up, down, top and bottom and other like termsindicating relative positions to a given point or element are may beutilized to more clearly describe some elements. Commonly, these termsrelate to a reference point such as the surface from which drillingoperations are initiated.

With reference generally to FIGS. 2 to 10 example embodiments oflubricators for use in plunger lift systems are described. FIG. 2illustrates a well system 5 incorporating a plunger lift system 7 inaccordance to one or more aspects of the disclosure. Plunger lift system7 includes a lubricator 10 in accordance to one or more aspects of thedisclosure positioned at the top of a production string 12 (tubingstring) to cushion the arrival of a plunger 14 (i.e., piston) thatcyclically travels a length of the production string 12. Plunger 14 maybe a bypass or a solid plunger. The depicted plunger 14 is illustratedas a bypass type of plunger having an internal passage that isselectively blocked by a valve element 16 (e.g., ball, dart, etc.).

The lubricator 10 is a special piping arrangement installed for plungerlift to capture the cycling plunger 14 at the top of the well. Inaccordance to embodiments the lubricator 10 includes an arrival spring18 (mechanical or gas), which cushions the arrival of a plunger withinthe lubricator 10, and one or more radial fluid outlets 20 each formedin an associated outlet pipe connector 22 to connect the lubricator tothe surface production pipe 24. The lubricator 10 may include one ormore catchers 26 adapted to selectively hold the plunger 14 within thelubricator. In accordance to some embodiments the catcher may bearranged with an outlet pipe connector.

The well system 5 includes a borehole 28 extending from a surface 30 ofthe earth to a producing formation 32. Wellbore 28 may be lined with acasing 34 including perforations 36 proximate the producing formation.The surface end of the casing is closed at the surface by a wellheadgenerally denoted by the numeral 38 having a valve 40 located below orupstream of the lubricator toward the producing formation. Theproduction string 12 extends down the wellbore inside of the casing. Abumper spring 42 is positioned at the lower end of the tubing string 12to stop the downward travel of the plunger 14.

Formation fluid 44 enters the casing through the perforations and intothe tubing string for example through a standing valve 46. The freetravelling plunger 14 is lifted from the bottom of the well to thesurface when the lifting gas energy below the plunger is greater thanthe liquid load 48 and gas pressure above the plunger. In a plunger liftsystem operation, the well is shut-in by closing for example a flowcontrol valve 25 for a period of time during which sufficient formationpressure is developed within the casing to move the plunger 14 and theliquid slug 48 that is above the plunger upward to the surface when theflow control valve is opened.

With reference in particular to FIGS. 2-10, the plunger lift lubricator10 generally includes a lower vertical lubricator section 11 forming avertical bore 54 and extending between a top end 56 connected to aspring housing 52 carrying the arrival spring 18 and a bottom end 58 tobe connected to a wellhead. The lower vertical section comprises a flowbody 50 and a radial outlet 20 formed in a pipe connector 22. Accordingto aspects of the disclosure the lower lubricator section 11 does notinclude welded connections. FIGS. 3-6 illustrate a lower lubricatorsection 11 that is constructed, via forging or machining, as a singlepiece including the top and bottom connection profiles 56, 58 and theone or more outlet pipe connectors 22. FIGS. 7-9 illustrate embodimentsof a lower lubricator section 11 formed of interconnected elementswithout welding. FIG. 10 illustrates a non-limiting example of a catcher26.

Referring first to FIGS. 3-6, the spring housing 52 is connected to thetop end 56 of the flow body via threading to allow for removal of thespring housing when needed. The bottom end 58 is adapted to connect tothe wellhead. Each of the flow bodies 50 illustrated in FIGS. 3-6 have aflange type profile at the lowermost end 58 for connecting with thewellhead, however, a threaded connection may be utilized. In accordanceto some embodiments, the lowermost end 58 is machined, forged, or castwith the flange profile to avoid the weakness of welding a flangeprofile onto the flow body.

The flow body 50 includes one or more radial production outlets 20. Eachoutlet 20 is formed through an outlet pipe connector 22 which is formedas a single unit with the flow body 50 in FIGS. 3-6. The pipe connector22 forms a horizontal passage 66 extending from the radial outlet 20 andlubricator bore 54 through a pipe connector profile 68 for connecting tothe surface production piping 24 (FIG. 2). In FIGS. 3 and 4 the pipeconnector profile 68 is a thread profile. In accordance to someembodiments, the thread profile 68 is an Acme thread profile, such as a14.5 degree thread profile. In FIGS. 5 and 6 the connector profile 68 isa flange profile. The outlet pipe connector 22 is forged, machined orcast with the flow body 50 eliminating the welded connection of a threador flange connector profile 68.

In accordance to some embodiments, the outlet pipe connector 22 includesa catcher 26 for example as described below with particular reference toFIG. 10. In the non-limiting illustrated embodiments, the catcher 26 isaligned for example 180 degrees from the horizontal passage 66.

With reference in particular to FIGS. 3-6, the flow body 50 is machined,forged or cast as a one-piece unit including the outlet pipeconnector(s) 22 and the connection profiles on the terminal ends 56, 58from a single piece (billet) of material. The flow body 50 may beconstructed for example of an alloy compound including but not limitedto carbon, stainless steel, or other corrosion resistant materials. Inaccordance to an embodiment a billet of material receives astress-relieving heat-treatment from the supplying mill at the time ofmanufacture and carries a Rockwell hardness rating of 22 or less (Rc22).Above 22Rc, steel will not pass the Charpy impact test and is deemedunsuitable for cold service.

The lubricator bore 54 may include one or more internal diameters. Forexample, in FIGS. 3-6 the lubricator bore 54 comprises a top passage 70portion proximate to the top end 56 having a different diameter than alower passage 72 portion extending below the top passage portion. In theillustrated embodiments, the top passage 70 has a larger diameter thanthe lower passage 72. With reference to FIG. 3, the lower end 74 of thespring housing 52 is positioned inside the top passage 70 and aninternally threaded collar 76, which is rotationally attached to thespring housing 52, connects with the external threads on the top end 56of the flow body 50. A seal (e.g., O-ring) 78 is disposed with the lowerend 74 of the spring housing to seal the connection with the flow bodyand lubricator bore. The addition of seal 78 provides for additionalsealing capability in particular in the event that the spring housing 52and flow body 50 are misaligned during connection. A striker element 80may be disposed with the arrival spring 18 and located at leastpartially within the top passage 70 portion of the flow body. Theillustrated striker element 80 is a striker block for use for examplewith a plunger having a male fish neck profile. The striker element 80can take various forms. In some embodiments the striker element 80 willinclude a rod to extend into the internal passage of the plunger to movethe valve element to the open position.

In the illustrated embodiments the uppermost end 56 is defined by athread profile without the aid of the welding process. The threadprofile of the uppermost end 56 conforms to a 14.5 degree Acme profilein at least one embodiment, representing a strong, pressure resistantdesign, unlike the common V-thread. In accordance to some embodiments,the thread profile of the outlet pipe connector profile 68 conforms to a14.5 degree profile to maintain the integrity of the seal bywithstanding the pressure induced stress.

Square threads have a zero-degree thread flank angle and induce lessfriction than a 14.5 degree Acme profile and therefore may be preferredfor maximal applied axial force to engage the sealing element into aleak-tight joint. However, the square thread profile is subject toloosening, especially in the presence of the type of vibration thatoccurs periodically within a flowing fluid stream that is intermittentlypressurized with gas then liquid. In accordance with an embodiment asquare thread may be utilized with an anti-rotation, thread lockingdevice to secure a non-locking, square thread.

Common 60 degree V-threads, whether straight or tapered, induce unduefriction during the tightening process because the vector of the threadangle directs 30% of the force generated during the tightening processin a direction perpendicular to the preferred axis. Consequently, thecommon, 60 degree V-thread may not impart sufficient axial force toengage the mating surfaces of the surface piping into the concavesurface of the lubricator outlet profile. The common V-thread is definedby its seal-tight thread. In profile, the thread is tapered along itslength which causes the male profile to wedge into the female profile asthe threads are tightened. For the pressurized fluid to escape it mustmigrate the length of the spiral path of the thread engagement, a taskmade difficult by the presence of the sealant compound. The Acme threadtaught herein is a straight thread in profile wherein the spiral profilemaintains a constant diameter along its length. Sealing does not takeplace within the thread itself The seal occurs when the engagement ofthe thread acts to bias two mating surfaces into a sealing contact.These two surfaces are each defined by a radius shape, one concave andthe other convex, hence, the allowance for a slight misalignment. The14.5 degree thread profile carries a greater sheer resistance becausethe profile of the thread is wider at its base when compared to a squarethread profile.

Acme threads (14.5 degree) are considerably stronger against the forcesof thrust versus V-thread. At 14.5 degrees, the Acme thread flankprofile combines the correct balance of thread-locking friction with theultimate holding power of the material's yield strength. Thiscombination resists the axial movement generated by the force of theinternal pressure as well as resistance to rotational creep.

Referring now to FIGS. 7-9, the lubricator 10 includes a lowerlubricator section 11 formed of multiple elements that areinterconnected without welding. In the illustrated embodiments, thevertical lubricator bore 54 of the lower lubricator section 11 is formedof a flow body 50 having the bottom connector profile 58, one or moreoutlet pipe connectors 22, and an adaptor 60 carrying the top connectorprofile 56 for connection with a spring housing 52. In the illustratedembodiments the lower lubricator elements 50, 22, 60 are interconnectedat non-threaded flanges. In FIG. 7 a portion of the lubricator bore 54adjacent to the radial outlet 20 is shown with an enlarged diameterrelative to the bore 54 at the bottom end 58 to dispose a liner asillustrated in FIGS. 8 and 9. Although all of the single outletlubricators are shown as including a liner as further described below,the single outlet lubricators do not require a liner.

The outlet pipe connector 22 comprises a body 62 formed of a singlepiece of material such as an alloy compound including but not limited tocarbon, stainless steel, or other corrosion resistant materials. Inaccordance to an embodiment a billet of material receives astress-relieving heat-treatment from the supplying mill at the time ofmanufacture and carries a Rockwell hardness rating of 22 or less (Rc22).Above 22Rc, steel will not pass the Charpy impact test and is deemedunsuitable for cold service. In the illustrated examples the outlet pipeconnector is formed from a square shaped raw material and may retain thesquare shape when completed.

The outlet pipe connector 22 comprises a vertical throughbore 64 formingpart of the lubricator bore 54 and extending between top and bottomsurfaces 82, 84 or flange profiles. A horizontal passage 66 extendsradially from vertical throughbore 64 to a surface pipe connectionprofile 68 for connection with the surface piping 24 (FIG. 2). Thesurface pipe connection profile 68 may be a threaded or flange type ofprofile. In accordance to embodiments the flange profiles 68, 82, 84 maybe the planar or substantially planar outer surface of the outlet pipeconnector 22. In the illustrated examples, the flange profiles of theoutlet pipe connector 22 may include threaded sockets 90 for receivethreaded elements (e.g., studs or bolts) 92 or may comprise threadedelements 92 on which the flange profiles of the respective adaptor 60,flow body 50 and surface piping can be attached. In accordance to someembodiments, the outlet pipe connector 22 includes a catcher 26 forexample as described below with particular reference to FIG. 10. In thenon-limiting illustrated embodiments, the catcher 26 is aligned forexample 180 degrees from the horizontal passage 66.

The flow body 50 is made as a one-piece unit, machined, forged or castfrom a single piece of material, along a single vertical axis of amaterial such as used to form the outlet pipe connector 22. The lowerend 58 of the flow body 50 is formed with a connection profile adaptedfor connecting with a wellhead. In the illustrated examples the lowerend profile 58 is a flange profile. The flow body 50 has a topflange-type connection profile 86 for connection with the bottomflange-type connection profile 84 of the outlet pipe connector 22. Theflow body 50 has a vertical throughbore 65 forming part of thelubricator bore 54 and extending from the bottom end 58 to the top end86.

Adaptor 60 is made as a one-piece unit, machined, forged or cast from asingle piece of material, of a material such as used to form the outletpipe connector 22 and flow body 50. Adaptor 60 has a verticalthroughbore 67 extending from the top end 56 to the bottom flange-typeconnection profile 88 connected to the top flange connection profile 82of the outlet pipe connector 22. In accordance to some embodiments, thetop threaded profile 56 and or a threaded connector profile 68 conformsto a 14.5 degree Acme profile in at least one embodiment, representing astrong, pressure resistant design, unlike the common V-thread.

With reference to FIGS. 2-10, the lower lubricator section 11 mayinclude one or more horizontally oriented pipe outlets 20. Two or moreoutlets 20 are traditionally utilized to reduce or remove thepossibility of the plunger 14 from blocking the flow path of theproduced fluid from the production string through the lubricator andinto the surface piping. If the plunger blocks a first horizontal outlet20 the wellbore fluid can be produced from one or more of the additionalvertically spaced horizontal outlets 20.

Relative to a multiple outlet lubricator, a single outlet reduces thecost of manufacturing and the costs in the related surface piping. Toremove or reduce the possibility of the traveling plunger 14 blockingthe flow path of the up-flowing fluid from within the wellbore, thesingle outlet 20 lubricator may comprise an annular passageway 94 thatallows the wellbore fluid to bypass the plunger 14 within the lubricatorto pass through the outlet 20 into the surface piping as illustrated forexample in FIGS. 3, 6, and 8-10. In accordance to embodiments, theannular passage 94 is formed between a perforated liner 96 disposed inthe lubricator bore 54 adjacent to the outlet 20 and the inner wall 98forming the lubricator bore. The perforated liner 96 includes openings100 to allow fluid to pass radially through the liner. In accordance tosome embodiments, an opening 100 may be sized and positioned to pass apin element of a catcher 26, see e.g. FIG. 10.

FIG. 10 illustrates an example of a catcher 26 which may be utilizedwith a lubricator section 11. Catcher 26 includes an element 102, suchas pin, adapted to selectively engage a plunger 14 (e.g., FIG. 8) whenit is located in the lubricator bore 54. In the illustrated example thepin 102 is biased by a spring 104. In accordance to some embodiments thecatcher 26 is automated and operated by an actuator. Pin 102 is moveablydisposed in a radial passage 106 formed for example through the outletpipe connector 22 and extending from the outer surface 63 to thelubricator bore 54. In accordance to some embodiments, the pin passage106 is located about 180 degrees from the horizontal outlet passage 66.An end piece 108 is connected with the body 62 of the outlet pipeconnector 22 over the pin passage 106. In the illustrated example, theend piece 108 is connected with a non-welded fastener 110, e.g., ascrew, to avoid a welded connection. The end piece may be connected viawelding in some embodiments.

The foregoing outlines features of several embodiments so that thoseskilled in the art may better understand the aspects of the disclosure.Those skilled in the art should appreciate that they may readily use thedisclosure as a basis for designing or modifying other processes andstructures for carrying out the same purposes and/or achieving the sameadvantages of the embodiments introduced herein. Those skilled in theart should also realize that such equivalent constructions do not departfrom the spirit and scope of the disclosure, and that they may makevarious changes, substitutions and alterations herein without departingfrom the spirit and scope of the disclosure. The scope of the inventionshould be determined only by the language of the claims that follow. Theterm “comprising” within the claims is intended to mean “including atleast” such that the recited listing of elements in a claim are an opengroup. The terms “a,” “an” and other singular terms are intended toinclude the plural forms thereof unless specifically excluded.

What is claimed is:
 1. A plunger lift lubricator, comprising: a lowerlubricator section having an internal lubricator bore extending axiallyfrom a top thread profile to a bottom flange profile; and an outlet pipeconnector comprising a body having a vertical throughbore forming aportion of the lubricator bore and a radial passage extending through apipe connector profile to the vertical throughbore.
 2. The plunger liftlubricator of claim 1, wherein the outlet pipe connector comprises aliner disposed in the lubricator bore; and an annular passage betweenthe liner and an inner wall of the lubricator bore.
 3. The plunger liftlubricator of claim 1, wherein the top thread profile conforms to a 14.5degree Acme profile.
 4. The plunger lift lubricator of claim 1, whereinthe pipe connector profile of the outlet pipe connector is a threadprofile that conforms to a 14.5 degree Acme profile.
 5. The plunger liftlubricator of claim 1, wherein the top thread profile conforms to a 14.5degree Acme profile; and the pipe connector profile of the outlet pipeconnector is a thread profile that conforms to a 14.5 degree Acmeprofile.
 6. The plunger lift lubricator of claim 1, comprising a springhousing threadedly connected to the top thread profile.
 7. The plungerlift lubricator of claim 1, further comprising a spring housing haying alower end disposed within a top passage of the top thread profile; and aconnector attached to the housing and threadedly connected to the topthread profile.
 8. The plunger lift lubricator of claim 7, wherein theoutlet pipe connector comprises a liner disposed in the lubricator bore;and an annular passage between the liner and an inner wall of thelubricator bore.
 9. The plunger lift lubricator of claim 7, wherein thepipe connector profile of the outlet pipe connector is a flange profile.10. The plunger lift lubricator of claim 7, wherein the outlet pipeconnector comprises a liner disposed in the lubricator bore; and anannular passage between the liner and an inner wall of the lubricatorbore.
 11. The plunger lift lubricator of claim 1, wherein the lowerlubricator section is formed of a single piece of material including thetop thread profile, the bottom flange profile, and the outlet pipeconnector and the pipe connector profile.
 12. The plunger liftlubricator of claim 11, wherein the outlet pipe connector comprises aliner disposed in the lubricator bore; and an annular passage betweenthe liner and an inner wall of the lubricator bore.
 13. The plunger liftlubricator of claim 11, where the pipe connector profile is flangeprofile.
 14. The plunger lift lubricator of claim 11, further comprisinga spring housing having a lower end disposed within a top passage of thetop thread profile; and a connector attached to the housing andthreadedly connected to the top thread profile.
 15. The plunger liftlubricator of claim 14, wherein the outlet pipe connector comprises aliner disposed in the lubricator bore; and an annular passage betweenthe liner and an inner wall of the lubricator bore.
 16. The plunger liftlubricator of claim 1, wherein the lower lubricator section comprises:the outlet pipe connector formed of a single piece of material, whereinthe vertical throughbore extends between a top surface and a bottomsurface; a flow body formed of a single piece of material having avertical throughbore forming a portion of the lubricator bore andextending from the bottom flange profile to a top flange profile that isconnected to the bottom surface of the outlet pipe connector; and anadaptor formed of a single piece of material having a verticalthroughbore forming a portion of the lubricator bore extending from thetop thread profile to a bottom flange profile that is connected to thetop surface of the outlet pipe connector.
 17. The plunger liftlubricator of claim 16, wherein the outlet pipe connector comprises aliner disposed in the lubricator bore; and an annular passage betweenthe liner and an inner wall of the lubricator bore.
 18. The plunger liftlubricator of claim 16, further comprising a spring housing having alower end disposed within a top passage of the top thread profile; and aconnector attached to the housing and threadedly connected to the topthread profile.
 19. The plunger lift lubricator of claim 16, wherein thepipe connector profile of the outlet pipe connector is a flange profile.20. The plunger lift lubricator of claim 16, wherein the pipe connectorprofile of the outlet pipe connector is a thread profile.